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Robin nest box size

When building a Robin nest box or buying one, you'd probably want to know the most effective nest box interior measurements.

Robin next box size will be 200mm high with a 100mm minimum entrance hole, well offering an additional 120mm or so hideaway nesting area. Minimum depth of 200mm to 250mm should correspond to width measurements. This is a minimum size, but can be a larger square box.

As we go into detail of the minimum measurements of Robin nest box, bare in mind, bird boxes vary in size and design greatly.

And well our measurements take into consideration a square wooden nest box, ceramic or woodcrate boxes have varied sizin

Meeting the minimum requirements is recommended, it really doesn't matter if they don't tick all boxes.

In the end it will be the Robin that wants to set up a nest that will judge whether it is suitable for laying eggs.

Once you've drawn up your box design or researched a decent box to buy, again its not just sizing, but a Robin nest box location plays a vital part in a Robin taking to it or not.

As little as 5 or 6 panels of wood will only be needed to make up the structure of the box; 2 sides panels, single front panel, roof, base and a back panel.

No need for a hinge or opening panel as the large open fronted entrance hole should be significant enough to access for cleaning out when the nesting season is over.

All measurements outlined below should be minimum interior box sizing targets only, well outside dimensions will make the box much larger, though are not important.

Minimum 200mm box height

To meet the minimum height for the total box size height, you will need to rely on the 2 side panels meeting these requirements.

Whatever you cut the side panels to, will be the total height of the box. Its only the roof or base panel that will add additional height or loss.

Well the base panel could be fixed to the bottom on the outer side, you'd lose up to 18mm in the total height if fixing the panel on the inside.

Whereas the panel roof - regardless if its a flat top or angled - will gladly sit on top of the box with a little overhang on the front.

Overall, this is all a minimum height that will satisfy Robins wishing to setup a nest in your garden, but you can go taller if you need to.

As a matter of fact the height could be as much has 300mm, with a deep nesting site tucked behind the lower wooden panel.

200mm to 250mm depth

Measuring the depth replies on the side panels again, and depends on what the width of the side panels were original cut from.

If the panel is 200mm then that was probably the original width of the plank of wood it was cut from.

Which suites us just fine as a 200mm box depth is the minimum requirement for Robins.

It can be much wider but what you want here is a depth that matches the total width of the nest box, so we end up with a perfect square or rectangular box shape.

No loss of the depth will be lost during construction, as the side panels are fixed to the back panel, well the additional front bottom panel is fixed to the outside.

Well the depth will match the width, it is possible to make the total depth deeper, as to make sure there is space inside for lots of nesting material that will be used.

Deep bird box will also help the Robin sit the nest further back away from the open front well offering a more secure way to keep the eggs safe.

Width inherits depth sizing

Whatever size you'd gone for with the total depth of the box, this measurement is then carried forward for the width of the box.

That would mean you end up with a perfect square box which will measure 200mm by 200mm - give or take several millimetres.

Bird box width will only apply to wooden bird boxes, as the more complicated, made from natural materials boxes will have a width that is hard to measure - such as rounded log boxes.

With square Robin boxes we can hit that 200mm minimum target which is easy in wood.

Absolute width of box can vary greatly depending on box design, it could have an angle which would make the top or bottom narrower, or...

It could be a rounded or triangle shaped box that changes the total width enormously.

Entrance hole will be 100mm high

Regardless of Robin nest box sizing, a minimum requirement for the entrance hole should be 100mm high.

Its not important the entrance hole width, just as long has you reach the minimum height.

Depending on bird box design this can vary greatly, but as it happens this minimum requirement is not always met.

Robins will have the final say but its very possible they will take to a box that doesn't have that all important 100mm height.

If it doesn't then we can put the blame squarely on the box design and material, with log or ceramic boxes using a more curved, shaped entrance hole that loses the minimum requirement.

Reaching the minimum entrance hole requirement should always be met in wooden boxes, there's really no excuses.

To reach a suitable entrance hole width, this will depend on the total width of the box; thus the front panel will simply be fixed on to create a sort of hideaway for the nest.


All recommended measurements outlined only refer to interior dimensions only, well the total box size will be much larger then you thought.

Minimum requirement for the Robin nest box height and depth is 200mm to 250mm, and anywhere in between.

No loss of the interior measurements will be lost as the base, roof and front panel are usually nailed or screwed to the outside edges, with no chance of losing inside space.

Whatever the depth of the box would usually be the width; though an entrance hole of 100mm height should be met.

Entrance hole width doesn't matter as much but should be the same as the height, so you'll have a large square open front entrance.

In the end, Robins will judge whether your box will meet all requirements, though its possible those made from wood will see more success.

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